Polycarbonates are well known engineering thermoplastics that are useful for diverse applications which require high performance polymers. However, it is desirable to upgrade the impact strength of compositions containing these polymers, to improve the processability of compositions containing polymers and to improve the re-extrudability of compositions containing these polymers.
In U.S. Pat. No. 3,130,177, compositions that consist of a polycarbonate and an ABS copolymer are described. West German Pat. No. 1,109,884 describes compositions of a polycarbonate with styrene acrylonitrile-styrene resins. U.S. Pat. No. 3,880,783 describes transparent compositions of a particular group of polycarbonates that may include ABS polymers.
The present invention is based on the novel concept of combining a polycarbonate resin, a multiphase composite acrylic interpolymer which is based on a C.sub.1-5 acrylate and a C.sub.1-5 methacrylate and a copolymer which comprises acrylonitrile, butadiene and an alkenyl aromatic compound to form a thermoplastic molding composition having improved impact strength and ductility. In addition, these compositions have enhanced thermal aging properties and enhanced weld line strengths.